I really researched lenses these lenses (this one and the 28-75 f/2.8) before I bought them... and I can say I have been EXTREMELY happy with photo quality.

I don't use this lens much, but when I need the wider shot, it comes right out and serves up excellent quality photos. I love the fact that it's widest aperture is f/2.8-4! I only buy "fast glass" so this was a great affordable option in the wider range.

Right out of the box it performed marvelously on my 20D. I have no doubts that if I needed wider shots more often, it would be one of my favorite lenses. Tamron has served up a great set with this and it's 28-75.

Great all-around range -- comfortable and natural fit with my camera (20D) -- not to heavy, not to light -- price!

Cons:

Have had the occassional focus issue with objects further than 30ft away

I have been using this lense for nearly 7 months (since January, '05) and could not be more pleased. It is the lens most commonly mounted to my camera for all-around shooting.

It is sharp throughout it's range and aperture. I DID have to have it calibrated when I first purchased it, but Tamron was great to deal with and I was extremely satisfied with the results. Considering the price difference between this lens and it's comparable Canon 24-70 f/2.8, I had no gripes with sending it in for Calibration and ending up with near-L quality photos.

The Lens Hood included was a nice bonus, and the fact it reverse mounts right on the lens for easy storage is a nice feature... the camera w/lens and hood are always together in my bag.

It is a nice weight - not too heavy, but not to light, which creates a nice balanced feel when on the camera.

I've found the 28-75 range to be perfect for all-around use. Though there have been times I wished for just a tiny bit more reach, there's no way I would trade this lens for the canon 17-85. 28-75, f/2.8 throughout is wonderful!

If you're never going to be taking pictures out in the pouring rain, I'd recommend this lens to ANYONE who likes this range and doesn't want to spend $1000.00 on the Canon equivalent. While it isn't weather-sealed like the 24-70L, the picture quality is just as good.

I have run into very occassional focus issues on object more than 30 feet away, but overall I've been MORE than happy with this lens! It is my favorite, and just about lives on my 20D.